1 /* ==================================================================== 2 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in 13 * the documentation and/or other materials provided with the 14 * distribution. 15 * 16 * 3. All advertising materials mentioning features or use of this 17 * software must display the following acknowledgment: 18 * "This product includes software developed by the OpenSSL Project 19 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 20 * 21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 22 * endorse or promote products derived from this software without 23 * prior written permission. For written permission, please contact 24 * openssl-core@OpenSSL.org. 25 * 26 * 5. Products derived from this software may not be called "OpenSSL" 27 * nor may "OpenSSL" appear in their names without prior written 28 * permission of the OpenSSL Project. 29 * 30 * 6. Redistributions of any form whatsoever must retain the following 31 * acknowledgment: 32 * "This product includes software developed by the OpenSSL Project 33 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 34 * 35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 46 * OF THE POSSIBILITY OF SUCH DAMAGE. 47 * ==================================================================== 48 * 49 * This product includes cryptographic software written by Eric Young 50 * (eay@cryptsoft.com). This product includes software written by Tim 51 * Hudson (tjh@cryptsoft.com). */ 52 53 #ifndef OPENSSL_HEADER_ECDSA_H 54 #define OPENSSL_HEADER_ECDSA_H 55 56 #include <openssl/base.h> 57 58 #include <openssl/ec_key.h> 59 60 #if defined(__cplusplus) 61 extern "C" { 62 #endif 63 64 65 /* ECDSA contains functions for signing and verifying with the Digital Signature 66 * Algorithm over elliptic curves. */ 67 68 69 /* Signing and verifing. */ 70 71 /* ECDSA_sign signs |digest_len| bytes from |digest| with |key| and writes the 72 * resulting signature to |sig|, which must have |ECDSA_size(key)| bytes of 73 * space. On successful exit, |*sig_len| is set to the actual number of bytes 74 * written. The |type| argument should be zero. It returns one on success and 75 * zero otherwise. */ 76 OPENSSL_EXPORT int ECDSA_sign(int type, const uint8_t *digest, 77 size_t digest_len, uint8_t *sig, 78 unsigned int *sig_len, EC_KEY *key); 79 80 /* ECDSA_verify verifies that |sig_len| bytes from |sig| constitute a valid 81 * signature by |key| of |digest|. (The |type| argument should be zero.) It 82 * returns one on success or zero if the signature is invalid or an error 83 * occured. */ 84 OPENSSL_EXPORT int ECDSA_verify(int type, const uint8_t *digest, 85 size_t digest_len, const uint8_t *sig, 86 size_t sig_len, EC_KEY *key); 87 88 /* ECDSA_size returns the maximum size of an ECDSA signature using |key|. It 89 * returns zero on error. */ 90 OPENSSL_EXPORT size_t ECDSA_size(const EC_KEY *key); 91 92 93 /* Low-level signing and verification. 94 * 95 * Low-level functions handle signatures as |ECDSA_SIG| structures which allow 96 * the two values in an ECDSA signature to be handled separately. */ 97 98 struct ecdsa_sig_st { 99 BIGNUM *r; 100 BIGNUM *s; 101 }; 102 103 /* ECDSA_SIG_new returns a fresh |ECDSA_SIG| structure or NULL on error. */ 104 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_new(void); 105 106 /* ECDSA_SIG_free frees |sig| its member |BIGNUM|s. */ 107 OPENSSL_EXPORT void ECDSA_SIG_free(ECDSA_SIG *sig); 108 109 /* ECDSA_do_sign signs |digest_len| bytes from |digest| with |key| and returns 110 * the resulting signature structure, or NULL on error. */ 111 OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign(const uint8_t *digest, 112 size_t digest_len, EC_KEY *key); 113 114 /* ECDSA_do_verify verifies that |sig| constitutes a valid signature by |key| 115 * of |digest|. It returns one on success or zero if the signature is invalid 116 * or on error. */ 117 OPENSSL_EXPORT int ECDSA_do_verify(const uint8_t *digest, size_t digest_len, 118 const ECDSA_SIG *sig, EC_KEY *key); 119 120 121 /* Signing with precomputation. 122 * 123 * Parts of the ECDSA signature can be independent of the message to be signed 124 * thus it's possible to precompute them and reduce the signing latency. 125 * 126 * TODO(fork): remove support for this as it cannot support safe-randomness. */ 127 128 /* ECDSA_sign_setup precomputes parts of an ECDSA signing operation. It sets 129 * |*kinv| and |*rp| to the precomputed values and uses the |ctx| argument, if 130 * not NULL. It returns one on success and zero otherwise. */ 131 OPENSSL_EXPORT int ECDSA_sign_setup(EC_KEY *eckey, BN_CTX *ctx, BIGNUM **kinv, 132 BIGNUM **rp); 133 134 /* ECDSA_do_sign_ex is the same as |ECDSA_do_sign| but takes precomputed values 135 * as generated by |ECDSA_sign_setup|. */ 136 OPENSSL_EXPORT ECDSA_SIG *ECDSA_do_sign_ex(const uint8_t *digest, 137 size_t digest_len, 138 const BIGNUM *kinv, const BIGNUM *rp, 139 EC_KEY *eckey); 140 141 /* ECDSA_sign_ex is the same as |ECDSA_sign| but takes precomputed values as 142 * generated by |ECDSA_sign_setup|. */ 143 OPENSSL_EXPORT int ECDSA_sign_ex(int type, const uint8_t *digest, 144 size_t digest_len, uint8_t *sig, 145 unsigned int *sig_len, const BIGNUM *kinv, 146 const BIGNUM *rp, EC_KEY *eckey); 147 148 149 /* ASN.1 functions. */ 150 151 /* ECDSA_SIG_parse parses a DER-encoded ECDSA-Sig-Value structure from |cbs| and 152 * advances |cbs|. It returns a newly-allocated |ECDSA_SIG| or NULL on error. */ 153 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_parse(CBS *cbs); 154 155 /* ECDSA_SIG_from_bytes parses |in| as a DER-encoded ECDSA-Sig-Value structure. 156 * It returns a newly-allocated |ECDSA_SIG| structure or NULL on error. */ 157 OPENSSL_EXPORT ECDSA_SIG *ECDSA_SIG_from_bytes(const uint8_t *in, 158 size_t in_len); 159 160 /* ECDSA_SIG_marshal marshals |sig| as a DER-encoded ECDSA-Sig-Value and appends 161 * the result to |cbb|. It returns one on success and zero on error. */ 162 OPENSSL_EXPORT int ECDSA_SIG_marshal(CBB *cbb, const ECDSA_SIG *sig); 163 164 /* ECDSA_SIG_to_bytes marshals |sig| as a DER-encoded ECDSA-Sig-Value and, on 165 * success, sets |*out_bytes| to a newly allocated buffer containing the result 166 * and returns one. Otherwise, it returns zero. The result should be freed with 167 * |OPENSSL_free|. */ 168 OPENSSL_EXPORT int ECDSA_SIG_to_bytes(uint8_t **out_bytes, size_t *out_len, 169 const ECDSA_SIG *sig); 170 171 /* ECDSA_SIG_max_len returns the maximum length of a DER-encoded ECDSA-Sig-Value 172 * structure for a group whose order is represented in |order_len| bytes, or 173 * zero on overflow. */ 174 OPENSSL_EXPORT size_t ECDSA_SIG_max_len(size_t order_len); 175 176 177 /* Deprecated functions. */ 178 179 /* d2i_ECDSA_SIG parses an ASN.1, DER-encoded, signature from |len| bytes at 180 * |*inp|. If |out| is not NULL then, on exit, a pointer to the result is in 181 * |*out|. If |*out| is already non-NULL on entry then the result is written 182 * directly into |*out|, otherwise a fresh |ECDSA_SIG| is allocated. On 183 * successful exit, |*inp| is advanced past the DER structure. It returns the 184 * result or NULL on error. */ 185 OPENSSL_EXPORT ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **out, const uint8_t **inp, 186 long len); 187 188 /* i2d_ECDSA_SIG marshals a signature from |sig| to an ASN.1, DER 189 * structure. If |outp| is not NULL then the result is written to |*outp| and 190 * |*outp| is advanced just past the output. It returns the number of bytes in 191 * the result, whether written or not, or a negative value on error. */ 192 OPENSSL_EXPORT int i2d_ECDSA_SIG(const ECDSA_SIG *sig, uint8_t **outp); 193 194 195 #if defined(__cplusplus) 196 } /* extern C */ 197 #endif 198 199 #define ECDSA_R_BAD_SIGNATURE 100 200 #define ECDSA_R_MISSING_PARAMETERS 101 201 #define ECDSA_R_NEED_NEW_SETUP_VALUES 102 202 #define ECDSA_R_NOT_IMPLEMENTED 103 203 #define ECDSA_R_RANDOM_NUMBER_GENERATION_FAILED 104 204 #define ECDSA_R_ENCODE_ERROR 105 205 206 #endif /* OPENSSL_HEADER_ECDSA_H */ 207